单链表反转

我写的单链表反转  欢迎大家提意见   菜鸟一个

head表示当前的  pre是head前一个   next是head后一个

 

/*
* 单链表逆转
*/
class Node {
int value;
Node next;

public Node(int N_value) {
this.value = N_value;
}

public Node(int N_value, Node next) {
this.value = N_value;
this.next = next;
}

}

public class ListReverse {
private static void PrintList(Node head) {
while (head != null) {
System.out.print(head.value + " ");
head = head.next;
}
}

public static void main(String[] args) {
Node n5 = new Node(5);
Node n4 = new Node(4, n5);
Node n3 = new Node(3, n4);
Node n2 = new Node(2, n3);
Node n1 = new Node(1, n2);
PrintList(n1);
Node NewHead = Revert2(n1);
System.out.println("递归调用");
PrintList(NewHead);

System.out.println("非递归调用");
PrintList(Revert(NewHead));
}

/*
* 非递归调用
*/
private static Node Revert(Node n1) {
if (n1 != null) {
Node pre = null;
Node head = n1;
Node next = n1.next;
while (next != null) {
head.next = pre;
pre = head;
head = next;
next = next.next;
}
head.next = pre;
return head;

//递归调用
}else {
return null;
}
}

/*
* 递归调用
*/
private static Node Revert2(Node current) {
//current!=null 是拒绝空链表判断用的

if (current == null || current.next == null){
return current;
}
Node nextNode = current.next;
current.next = null;
Node reverseRest = Revert2(nextNode);
nextNode.next = current;
return reverseRest; //其实这里面每次return的节点都是一样的
}

}

 

 

 http://blog.csdn.net/beiyetengqing/article/details/7596554

 

http://poly.iteye.com/blog/1748272

 

感觉上面两个写的比我的好，学习一下